One-Wire Serial Communication

I've been hunting around here and on google for an answer to my question by alas have found nothing as of yet.

What I'm trying to do is firstly decode some PWM Serial Data sent from one device to another, however it's operational range is 0-12v. It's in an automotive environment. Is this possible?

Ideally then I'd like to turn it around and replace one of those devices with an Arduino. Essentially the reverse of before, again is it possible?

I'm fairly certain it is possible, not 100% sure on the hardware side of it though. I've found things like the MAX232 which "might" be useful but I'm not sure.

Any help would be greatly appreciated.

What I’m trying to do is firstly decode some PWM Serial Data sent from one device to another

PWM and Serial don’t go together as far as I know. The data is either PWM (on/off at varying duty cycle) or serial.

What is sending this “PWM Serial” data?

however it’s operational range is 0-12v. It’s in an automotive environment.

Then, it isn’t likely limited to 12V. 16V might be a more reasonable upper limit. Regardless, a voltage divider will manage to get the value to something that the Arduino can deal with.

Ideally then I’d like to turn it around and replace one of those devices with an Arduino.

Which one? Changing the receiver is easy. Changing the sender is a bit more difficult. Though not much.

Sorry for the late reply. I'm guessing it's going to be serial and some form of one wire communication.

I'm thinking it'll possibly be limited to 12 as it's from one computer to another. I know it only happens once when you first fire up the engine, after that there is nothing.

Sorry I don't think you have enough information for any meaningfully reply. Are you sure you are not dealing with a CAN bus here?